To make kimchi: Place cabbage in microwavable bowl. Add water. Cover and microwave on high 2 minutes, or until tender-crisp. Rinse with cold water and drain well.
In large bowl, mix vinegar, gochujang, fish sauce, garlic and ginger. Add steamed cabbage, daikon, carrot and onion; toss to coat. Cover and chill.
To make mango slaw: Mix cabbage, mango, carrot, onion, red bell pepper, cilantro, ginger, vinegar, salt and garlic. Cover and chill.
To make spicy sesame mayonnaise: Mix mayonnaise, sriracha, sesame oil and vinegar until well blended. Cover and chill.
Heat grill to medium and lightly oil grill rack. Grill bratwursts 8 minutes, or until internal temperature reaches 155 F.
Spread mayonnaise on rolls. Place grilled bratwurst on rolls and top with kimchi and slaw.